Doppler ultrasound is one of the most widely used medical imaging procedures. Even though Doppler ultrasound is commonplace in hospitals and clinics, there may be considerable heterogeneity in system performance between different devices. Therefore, testing of system performance and stability is critical. The generally accepted approach for verifying system performance and stability is to use a standard test device, commonly referred to as a phantom.
With regards to phantom design, there are two main phantom types. The first type uses a filament (string) driven by a motor and running on a set of pulleys. The filament is moved under water in a reservoir and a measuring transducer is placed in contact with the surface of the water to visualize the flow. The second phantom type uses blood-mimicking fluid in a simulated blood vessel, instead of a filament, while a pump creates controlled flow that can be imaged by the Doppler ultrasound system under test. These types of commercially available phantoms require a motor and external power and can be bulky, expensive, or require lengthy set-up times.